Engcom Virtual Slide Rule Demo

The Engcom Virtual Slide Rule is really just an educational demonstration of the slide rule for young folk. But, you can actually move the center slide area around to get an idea of how a slide rule worked.

For those who don't remember (probably most people), slide rules used to come in a variety of sizes and features. Pocket slide rules were small enough to fit in a shirt pocket (usually with a pocket protector) and didn't have as many functions as larger ones like the one shown below.

I bought that one at a fire sale at a local university bookstore for $1. In their heyday, slide rules could cost quite a bit more with better ones coming in leather cases. Slide rules were also two-sided with different functions on each side.

Finally, there were even circular slide rules (I don't think I used one of those though I remember seeing them). If anyone has a good historical slide rule site, please let us know about it.